The present invention relates to a semiconductor device and a method of manufacturing the same.
Earlier techniques include a so-called superjunction (SJ) power MOSFET (metal oxide semiconductor field effect transistor) described in “Proceedings of 2004 International Symposium Power Semiconductor Devices & ICs, Kitakyushu, p. 459-462,” for example.
The SJ-MOSFET can exceed a limit of theoretical performance determined by an Si (silicon) material, although Si is used as the material of the SJ-MOSFET. Moreover, in the SJ-MOSFET, p and n impurity regions are formed in a sandwich arrangement in a drift region of a body portion. In this structure, a depletion layer is extended in a horizontal direction, and thereby it is possible to simultaneously deplete the whole drift region, which has not been possible with earlier structures. Therefore, the structure can achieve a higher impurity concentration in a p-type region and lower on-resistance as compared to the earlier structures.